SIM card balance can be recharged using you credit card in your personal account.

In case you do not want to think where and how to recharge your credit,
then you can activate convenient automatic recharge feature in your personal account.

If you have purchased a recharge voucher on board of airBaltic flight, then you can recharge your balance the following way:

Take the recharge card.
Carefully scratch off the protective layer from the card.
Enter the airBalticcard Mobile function in your phone’s menu.
Select the Add Credit function from the menu.
A message "Please enter PIN" will appear on the display of your phone.
Enter the 16-digit PIN and press OK.
A message showing your balance recharge information will appear on the display of your phone. 

Or dial *146*098PIN# (where PIN is the 16-digit code taken from the recharge card). Press the "call" button.
A message showing your balance recharge information will appear on the display of your phone.